The present invention relates to a circuit-breaker including a moving assembly contained inside a casing filled with a dielectric gas under pressure, the moving assembly including a xe2x80x9cdrivexe2x80x9d first tube, and a second tube surrounding the first tube coaxially, said first and second tubes being connected together via a ring provided with perforations and equipped with a valve member and constituting a moving piston separating a compression chamber from a blast chamber, said first tube being situated on the same side of the ring as the compression chamber and its end connecting to said ring, a moving arcing contact support being situated on the same side of the ring as the blast chamber and being fixed rigidly, with no degrees of freedom, to said ring.
More particularly, the invention relates to a high-voltage circuit-breaker and to the mode of assembling the ring or piston firstly with the drive tube and secondly with an arcing contact support that is part of the moving assembly.
Currently, the drive tube is screwed into the ring with tightening torque being applied. The resulting coupling is then locked either by adhesive or by a locking screw, or else by deforming the material. The arcing contact support is fixed in the same way.
That type of coupling is unsatisfactory since it is difficult to assemble, requiring a large tightening torque, thereby deforming the long parts, in particular the drive tube.
It is difficult to lock the coupling: when adhesive is used, it is necessary to prepare the surfaces, the adhesive can run, and it is necessary to use a adhesive that withstands high temperatures.
If a locking screw is used as the locking means, such a screw requires a certain installation thickness.
Locking by means of deforming the material manually is not always repeatable.
If the parts are made of aluminum, it is impossible to assemble them together by means of screw threads because of seizing, and it is then necessary to perform surface treatment on one of the parts to be assembled together, which then requires further machining on the bearing surfaces in order to enable electricity to flow through.
In addition, in such known screw coupling, a groove is machined in the arcing contact support or else in the ring (piston) for the purpose of receiving a valve member. Such machining requires good accessibility, or else cutting out to be performed specially on the parts, and this excludes the use of valve members made of metal since the valve member must be stretched elastically while being fitted in order for it to be placed in the groove.
An object of the present invention is to provide a non-screw mode of coupling in order to eliminate the above-mentioned drawbacks.
The invention thus provides a circuit-breaker as defined above, wherein, with said ring having a bore of diameter D, said ring is provided with a groove of depth h and of width l at a distance x from its face that faces said compression chamber, that end of said first tube which is connected to said ring being provided with n gaps extending over an axial length L allowing n claws to project, the end of at least one of the claws being provided with a rim that is received in said groove in said ring, said ring being provided with one or more passageways angularly in register with each claw provided with a rim, and making it possible for the rim(s) to be inserted axially as far as said groove, and then for the tube to be turned to cause the rim(s) to penetrate into the groove portions that remain, and wherein said arcing contact support, which is tubular, is provided with n gaps and with n claws that are complementary to the gaps and claws of said first tube, the claws of said arcing contact support fitting into and filing the gaps situated between the claws on said first tube.
Another characteristic of the invention makes it equally possible to use a flexible valve member or a metal valve member. According to this characteristic, at a distance l1 from the end-walls of the gaps, said arcing contact support is provided with a flange of outside diameter Dl and that comes into abutment against said ring, means being provided for constituting a groove for receiving a valve member against that face of said ring which faces the blast chamber.
In a first embodiment of the invention, said rigid fixing whereby said arcing contact support is fixed rigidly to said ring is achieved by forcing the end of length l1 extending from said flange to the end walls of said gaps to penetrate into the bore of diameter D in said ring, the outside diameter of the claws being such that they penetrate into said bore freely, said means for constituting said groove for receiving a valve member comprising a bearing surface belonging to said ring, of inside diameter D and of outside diameter D2 such that D1 greater than D2 greater than D, and against which said flange bears.
In a second embodiment, said rigid fixing whereby said arcing contact support is fixed rigidly to said ring is achieved by fixing said flange by means of screws against that face of said ring which faces the blast chamber, the peripheral portion of that side of said flange which bears against said face being provided with a bearing surface for receiving said valve member, and thus forming said groove.